6) Suppose that the fictional kingdom of Kellytopia has GDP equal to $1 billion, the capital stock is $1.7 billion, and a labor force of 70 million. The production function is Y =AK NI-a , where a = 0.25. Using this production function, estimate total factor productivity for Kellytopia. A) 0.16 B) 1.31 C) 4.19 D) 6.44